ComScore has heard these disses, and it's saying, "Enough!" The web analytics company is putting out a big report next week on the effectiveness of Facebook advertising.

Contrary to what Reuters and GM are saying, comScore says the Facebook ads are effective. It released a summary of what it plans to release next week on its blog.

The key takeaway: "Facebook earned media is having a statistically significant positive lift on people’s purchasing of a brand."

ComScore doesn't reveal much more about the results, saying, "stay tuned" for more next week.

However, it did take some time to rip apart the Reuters report, which it says is flawed because it relied on a survey of users. The problem with surveys is, "People tend not to provide very accurate assessments of their own behavior. And their accuracy in recalling their own behavior over an extended period of time can be especially unreliable."

We'll keep our eyes peeled for the full report next week. In the meanwhile, we'll see if Facebook's stock, which has been smashed since the IPO gets any kind of lift from this positive news.

UPDATE: We talked to comScore. It said this report is more centered on "earned media" which is brand pages, and free social mentions in the Facebook newsfeed. That doesn't help Facebook's ad business. But, comScore says it believes there is a positive correlation between paid advertising and earned media.